1. Field of the Invention
The present invention relates to a printing technology and, more particularly, to an auto screen-printing method for IMR and injection molding application.
2. Description of the Related Art
Conventional IMR printing methods include transfer-printing, spray-painting, electroplating, and direct injection molding. The transfer-printing method is not economic because it requires a long warm-up time and causes a big loss during printing. Further, this method cannot show an outstanding metal coloring. The electroplating method is expensive and has limitations on colors. The direct injection molding method is the most popularly accepted printing method. However, this method can only print one specific color at every injection molding process, not practical for printing a multi-color design.
The present invention has been accomplished under the circumstances in view. It is one object of the present invention to provide an auto screen-printing method for use in IMR and injection molding, which eliminates the drawbacks of the prior art printing methods. It is another object of the present invention to provide an auto screen-printing method, which is practical for use in IMR and injection molding. It is another object of the present invention to provide an auto screen-printing method, which is practical for multi-color printing. According to the present invention, the auto screen-printing method for use in IMR and injection molding comprises the steps of: (a) printing a layer of transparent hardening agent on a roll of PET material by means of an auto screen printing press and then drying the printing, (b) printing four different color mixtures of ink and hardening agent one after another on the dried transparent hardening agent by means of an auto screen printing press and drying the four color mixtures respectively after each color printing, (c) printing a layer of backing ink on the color mixtures of ink and hardening agent by means of an auto screen printing press and then drying the layer of backing ink, and (d) setting the printed roll of PET material thus obtained in an injection-molding machine for injection-molding with a plastic material into the desired finished product.